Drill bit
AssigneeKabushiki Kaisha Miyanaga
InventorMasaaki Miyanaga
Life of this patent
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Abstract
A drill bit includes a pointed head and a bit shaft. A dust suction passage is formed in the bit shaft. A hole with an opening is formed in the pointed head or in a portion of the bit shaft, the portion being near a distal end of the bit shaft. The bit shaft includes a first portion, the first portion including a core and a rib. The core extends in an axial direction, and is thinner than the pointed head. The rib protrudes radially outward from a side surface of the core, and extends over an entire length of the first portion. The dust suction passage extends through the core in the axial direction.
Claims11
A drill bit comprising:
- a pointed head including a plurality of cutting edges, which are arranged in a radial manner with respect to a central axis;
- a bit shaft provided with the pointed head at its distal end;
- a dust suction passage formed in the bit shaft and extending in an axial direction;
- and
- a hole with an opening, the hole being formed in the pointed head or in a portion of the bit shaft, the portion being near the distal end of the bit shaft, wherein:
- the hole is in communication with the dust suction passage;
- the bit shaft includes a first portion, the first portion including a core and a rib;
- the core extends in the axial direction, and is thinner than the pointed head;
- the rib protrudes radially outward from a side surface of the core, and extends over an entire length of the first portion;
- wherein the dust suction passage extends through the core in the axial direction;
- and
- wherein the rib includes an expanding portion at its radially outer end portion, the expanding portion expanding in a circumferential direction.
A drill bit comprising:
- a pointed head including a plurality of cutting edges, which are arranged in a radial manner with respect to a central axis;
- a bit shaft provided with the pointed head at its distal end;
- a dust suction passage formed in the bit shaft and extending in an axial direction;
- and
- a hole with an opening, the hole being formed in the pointed head or in a portion of the bit shaft, the portion being near the distal end of the bit shaft, wherein:
- the hole is in communication with the dust suction passage;
- the bit shaft includes a first portion, the first portion including a core and a rib;
- the core extends in the axial direction, and is thinner than the pointed head;
- the rib protrudes radially outward from a side surface of the core, and extends over an entire length of the first portion;
- wherein the dust suction passage extends through the core in the axial direction;
- and wherein the bit shaft includes a second portion sandwiched between the pointed head and the first portion;
- on an outer peripheral surface of the second portion, there is no portion protruding radially outward from an outer peripheral surface of a columnar body that is concentric with the pointed head and whose diameter is substantially the same as that of the pointed head;
- at least a part of the outer peripheral surface of the second portion coincides with a part of the peripheral surface of the columnar body, which is concentric with the pointed head and whose diameter is substantially the same as that of the pointed head;
- and
- the opening of the hole is formed in the pointed head or in the second portion.
Dependencies are inferred from the claim text.